fix: Avoid memory unsafety when loading session from disk (#270)

src/sentry_session.c

@@ -51,13 +51,19 @@ sentry__session_new(void)
     if (!opts) {
         return NULL;
     }
-    const char *release = sentry_options_get_release(opts);
-    const char *environment = sentry_options_get_environment(opts);
+    char *release = sentry__string_clone(sentry_options_get_release(opts));
     if (!release) {
         return NULL;
     }
 
     sentry_session_t *rv = SENTRY_MAKE(sentry_session_t);
+    if (!rv) {
+        return NULL;
+    }
+
+    char *environment
+        = sentry__string_clone(sentry_options_get_environment(opts));
+
     rv->release = release;
     rv->environment = environment;
     rv->session_id = sentry_uuid_new_v4();
@@ -78,6 +84,8 @@ sentry__session_free(sentry_session_t *session)
         return;
     }
     sentry_value_decref(session->distinct_id);
+    sentry_free(session->release);
+    sentry_free(session->environment);
     sentry_free(session);
 }
 
@@ -139,6 +147,16 @@ sentry__session_from_json(const char *buf, size_t buflen)
         return NULL;
     }
 
+    sentry_value_t attrs = sentry_value_get_by_key(value, "attrs");
+    if (sentry_value_is_null(attrs)) {
+        return NULL;
+    }
+    char *release = sentry__string_clone(
+        sentry_value_as_string(sentry_value_get_by_key(attrs, "release")));
+    if (!release) {
+        return NULL;
+    }
+
     sentry_session_t *rv = SENTRY_MAKE(sentry_session_t);
     if (!rv) {
         return NULL;
@@ -148,11 +166,16 @@ sentry__session_from_json(const char *buf, size_t buflen)
 
     rv->distinct_id = sentry_value_get_by_key_owned(value, "did");
 
+    rv->release = release;
+    rv->environment = sentry__string_clone(
+        sentry_value_as_string(sentry_value_get_by_key(attrs, "environment")));
+
     const char *status
         = sentry_value_as_string(sentry_value_get_by_key(value, "status"));
     rv->status = status_from_string(status);
 
     rv->init = sentry_value_is_true(sentry_value_get_by_key(value, "init"));
+
     rv->errors = (int64_t)sentry_value_as_int32(
         sentry_value_get_by_key(value, "errors"));
     rv->started_ms = sentry__iso8601_to_msec(

src/sentry_session.h

@@ -20,8 +20,8 @@ typedef enum {
  * metadata.
  */
 typedef struct sentry_session_s {
-    const char *release;
-    const char *environment;
+    char *release;
+    char *environment;
     sentry_uuid_t session_id;
     sentry_value_t distinct_id;
     uint64_t started_ms;

tests/test_integration_stdout.py

@@ -3,6 +3,7 @@
 import sys
 import os
 import time
+import json
 from . import cmake, check_output, run, Envelope
 from .conditions import has_inproc, has_breakpad, has_files
 from .assertions import (
@@ -14,6 +15,7 @@
     assert_crash,
     assert_minidump,
     assert_timestamp,
+    assert_session,
 )
 
 
@@ -115,6 +117,42 @@ def test_multi_process(tmp_path):
     assert len(runs) == 0
 
 
+@pytest.mark.skipif(not has_files, reason="test needs a local filesystem")
+def test_abnormal_session(tmp_path):
+    cmake(
+        tmp_path,
+        ["sentry_example"],
+        {"SENTRY_BACKEND": "none", "SENTRY_TRANSPORT": "none"},
+    )
+
+    # create a bogus session file
+    db_dir = tmp_path.joinpath(".sentry-native")
+    db_dir.mkdir()
+    run_dir = db_dir.joinpath("foobar.run")
+    run_dir.mkdir()
+    with open(run_dir.joinpath("session.json"), "w") as session_file:
+        json.dump(
+            {
+                "sid": "00000000-0000-0000-0000-000000000000",
+                "did": "42",
+                "status": "started",
+                "errors": 0,
+                "started": "2020-06-02T10:04:53.680Z",
+                "duration": 10,
+                "attrs": {
+                    "release": "test-example-release",
+                    "environment": "development",
+                },
+            },
+            session_file,
+        )
+
+    output = check_output(tmp_path, "sentry_example", ["stdout", "no-setup"])
+    envelope = Envelope.deserialize(output)
+
+    assert_session(envelope, {"status": "abnormal", "errors": 0, "duration": 10})
+
+
 @pytest.mark.skipif(not has_inproc, reason="test needs inproc backend")
 def test_inproc_crash_stdout(tmp_path):
     cmake(